


It's Not the Mountaintops, It's the Walking in Between

by mtlstarsfan18



Category: Supergirl (TV 2015)
Genre: Alternate Universe - Soulmates, F/F, Soulmate-Identifying Marks, Soulmates
Language: English
Status: In-Progress
Published: 2019-04-18
Updated: 2019-04-23
Packaged: 2020-01-16 02:59:01
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 3,946
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18512509
Author URL: https://archiveofourown.org/users/mtlstarsfan18/pseuds/mtlstarsfan18
Summary: Lena's never had soulmate marks before, and as an unlovable Luthor, is shocked when a note appears. Kara's just arrived to Earth and doesn't even know what a soulmate is.OrThe one where Kara and Lena are soulmates and marks appear on both of them.





	1. Math Homework: #3-7

Lena got up and stretched slowly, placing her feet solidly on the carpet of her plush boarding school room. Her roommate, Bernice, still fast asleep across from her, snoring loudly. With an eye roll Lena pulled the curtains open, gazing out at the quad, and jumped in surprise. Written on her left arm in bright purple ink were the words  
_math homework: #3-7._

Lena certainly had not written it on her own skin, that’s what her day planner was for, and she immediately dashed into the bathroom attached to her dorm room. She leaned over the sink, vigorously washing her arm with water, and then soap but the mark would not remove itself. Her pale skin gleaned with the addition of soapy water, but the words remained steadfast. Leaning back on the sink, Lena gaped, taking it all in. 

While everyone else received sloppy marker drawings, fresh scars, and jotted notes from near birth, Lena’s skin had remained stubbornly empty. Bernice constantly had small notes from her soulmate, and they spoke on a regular basis from what Lena could gather. Even Lex had received some form of connection. 

Lena remembered being seven years old, standing in the grand library, asking why she had yet to receive any soul marks. Lillian had told her that she didn’t have a soulmate, and that Luthors didn’t need soulmates. Lionel and Lillian weren’t soulmates, but they were nonetheless successful in life. One did not need a soulmate to conquer the world. Lena had also been informed she was somehow so unlovable that she was destined to be alone forever, making her stomach churn but firmly sticking in her mind. She had taken that as gospel through the years, as her skin remained untouched albeit for her own scrapes and a few pen marks. 

Lena began to scan scenarios through her head, as she held the cold porcelain of the sink tightly. Her soulmate could be incredibly young, thirteen years her junior, but based on the neat note about maths homework that seemed unlikely. She could have not noticed the markings before, also an incredibly unlikely scenario as Lena prided herself on her neat, and cleanly appearance constantly. Her soulmate could have never written on their skin before and not gained any scars. Though highly unlikely, it did seem the most likely of the scenarios. 

Bernice’s long snore pulled Lena out of her stupor, and she walked back into their shared room. She yanked the drawer of her desk open, pulling out a black fine-liner, and plopping herself down into her desk chair. A whirlwind of thoughts went through her mind, what to write? These were going to be her first words to her soulmate, they needed to be powerful, important, and well thought out. Lena’s brain felt like someone had scrambled it around as she thought about what she could possibly write, there were endless possibilities. 

In the end, she settled on the most simple phrase she could think of. Simple, concise, and hopefully enough to get her soulmate to finally notice her. 

_Did you finish your maths homework? If not, I can help. -Lena._

Lena was not as well-versed on the soulmate rules as other youth her age, but she did know that the soul bond would blur out her last name, location, or any other attempt to find each other before your initial meeting. 

Running her fingers over the fresh ink, ascertaining it was dry, Lena admired her handiwork. Excitement bubbled through her as she looked eagerly at her arm to see if there would be a response. After a few minutes, and glancing at the alarm clock flashing and reading 6:45 A.M. her time, she realized her soul mate may be asleep among a host of other possibilities and resigned herself to going downstairs to the dining hall for breakfast. 

~~~~~~~~~~  
Kara sat incredibly confused in her math class. One of the boys at lunch had knocked her glasses, smashing them, and the whole world seemed far too intense and in focus for her liking. Everything was loud and powerful as she tried to focus on her teacher as she wrote out math problems on the board. Her three weeks on Earth were still not enough to teach her how to tune out all the excess, and she still felt very out of place. 

Diligently, she copied down everything on the board, scrambling to write down any additional facts the teacher added verbally. Her entire world was spinning as she tried to narrow in on what was important; figuring out this algebra problem. Pencils scratched on paper all around her, along with loud breathing and the screech of chalk filling her ears. 

Just as she was starting to mellow out more in class, and find ways to tune out the excess noise, the bell rang. She nearly jumped at the sound, and looked back up to the board where the teacher had written HW #3-7. As Kara stood up, her books spilled off her desk and onto the floor. She gathered them quickly, trying to stuff them into her backpack, but was taking far more time than anticipated. 

“Miss Danvers, you’ll want to be on your way”, the math teacher said as the warning bell sounded for the next class. 

Kara stood up, and raced out of the class, but not before remembering the homework she had to do. As she half-jogged down the hallway at an appropriate human pace, she pulled a purple pen out of her pocket. Her notebooks already packed away, she scribbled a note about the math homework on her forearm, trying to balance her book bag at the same time. 

_math homework: #3-7_


	2. An Explanation

An aggressive knock sounded on the door, bringing Kara out of her deep sleep as she shot up in bed. The door swung open violently, and there stood her older adoptive sister, Alex. Her brown hair was arranged messily around her shoulders, in a matching pajama set with beakers on it. Her arms were crossed, as she stood there radiating anger and aggression. 

“Eliza said I had to wake you up for school. Breakfast is almost ready.” 

Kara sat up in bed, rubbing her eyes as light streamed in through the curtains, and stared blankly at Alex. She was still waking up, and was taking longer to process things. 

“Breakfast. Now.” Alex enunciated, “are you even listening to me, you dumb alien?” She rolled her eyes, then walked out of sight of the door frame, and down the stairs. Kara pulled off the covers and put on a sweater overtop of her pajama shirt. She walked slowly downstairs, still a little bleary eyed, where Eliza had set up bacon and eggs for breakfast, arranged neatly on the dining room table. 

“Good morning sunshine!” Eliza smiled broadly at Kara, “I thought I would make you girls some power food before school. Your growing brains need it!” 

“G’morning”, Kara managed to say as she sat down at the table across from Alex, who was chewing thoughtfully on a piece of bacon, a physics book cracked open next to her. Kara reached across the table for syrup, hoping to drown her bacon in it to make it taste better, and then had her sleeve catch in a pitcher of orange juice, soaking it through. 

“Kara, sweetie, roll up your sleeves. You don’t want to be covered in breakfast foods”, Eliza said from by the sink, where she was rinsing a bowl of raspberries and grapes. Kara yanked her arm back. 

“Oh, sorry Eliza”. She pulled her sweater off and draped it over the back of the chair to dry, pushing up her pajama shirt sleeves. 

“Mom!” Alex said, “Kara has stuff written on her arm. You’re always telling me not to do that, why can she?” she grumbled, standing up with a piece of bacon still hanging out of her mouth. “I’m going to get dressed”. 

Eliza walked over to Kara, “sorry about Alex, but she is right, we don’t want you writing everywhere. Your body isn’t a notepad, we can get you a journal for that”, Eliza chuckled. She brought up the damp dish cloth in her hand to wipe the marks off Kara’s arm, the purple pen fading away. As Kara reached for another piece of bacon, Eliza began to scrub a bit more vigorously. “This won’t seem to come off”. She turned Kara’s arm towards her, and sucked a breath in. 

“Sweetie, did you write this?”, Eliza asked, looking at Kara softly. Kara turned her head to her arm where there was a message written in neat black handwriting. 

_Did you finish your maths homework? If not, I can help -Lena_

“No, I didn’t. I don’t know where it came from. I don’t even know a Lena”, Kara crinkled her nose in confusion. Eliza let out a breath, and turned Kara in her chair to face her. 

“Well, here on Earth, everyone has someone who they’re destined to be with, it’s called a soulmate”, Eliza started out slowly, “anything written on your soulmates’ body will also be on yours and vice versa. That goes for pen ink, and scars, and anything else that will leave a mark on you”. 

“So, I have someone who’s destined for me? And her name is Lena?” 

“Exactly. Jeremiah and I have the same connection. See?” Eliza said, showing her own arm where it read 

_Don’t forget to pick up milk El! -J_

“For now, you’ll only be allowed to see her first name, not her last name or where she is. Not until you meet at least. I know this is a lot to take in, but there is someone on Earth who is meant for you and only you”. Kara nodded slowly, her brain whirling in recognition. 

“How do I meet her? This Lena person”, Kara asked, suddenly curious about the person she was supposed to be with. 

“You don’t know yet. That’s the surprise.” Eliza pushed hair out of her own face and looked concerned for a moment. “Kar, it’s important that for now you don’t tell her your name”. Kara looked back quizzically, “your identity is secret and for your safety, at this point in time, you can’t tell her your name. You can write back, and call yourself K, and tell her about math homework and Alex and looking at the stars with Jeremiah, but you cannot tell her your name”. 

“But she told me hers.” Kara initially protested, bunching her fists up in agitation. 

“Yes, but protecting your identity is more important right now. You are so vulnerable and we can’t even let your soulmate know who you might be. No matter how many Karas there are in the world.” 

“Okay”, Kara sighed, thinking it through. “I understand, it’s about protecting me”. 

Eliza smiled back at her, “good girl, now go get ready for school and tell Lena you finished your math!”. 

Kara stood up quickly and rushed upstairs to her room. She rifled through her bedside table finding a sparkly pink pen, if this person was destined to her forever she was going to use the best, prettiest pen she could find. She then started to form perfect letters in her best handwriting, 

_I did finish my math homework. I don’t like math very much, do you? -K_

**Notes for the Chapter:**

> Thank you everyone for the support, it was super sweet! I know the chapters are a little short, but I'll have them coming every second day or so.


	3. Message Received

Lena sat in her third class of the day, calculus, surrounded by older students watching their teacher looking quite bored. The girl beside her was leaning on her elbow, almost slipping into sleep. Lena on the other hand was diligently taking notes, eager to prove herself in a class placing her four years ahead of her own age. 

As the teacher finished up with the lesson plan, Lena carefully dated her notes and recorded the homework in the colour coded day planner. It did not cost anything but time to be organized. She gathered her textbooks and notebooks, slotting them into her backpack and stood up to walk to her lunch break. 

As she arrived to the cafeteria Lex waved her over. He had senior lunch and would have to leave soon but he looked eager to see his sister, sweeping his pitch black hair out of his eyes. 

“Lena! They just released the school’s shortlist for the National Science Fair. Obviously we’re both on it. Congratulations”, he said slickly, patting her on the back. Lena grinned eagerly back, seeing a _congrats Lex!_ written sloppily on her brother’s arm, visible as his uniform sleeve was rolled up. 

“Thank you Lex, congratulations to yourself as well”, Lena said eloquently as Lex stood up to make it to his next class. Seeing the writing on Lex’s mark had reminded Lena of her own. She wanted to check, but wanted to be in private to do so. She carefully placed her backpack on the back of a chair facing the window, then stalked away to the bathroom. 

In the privacy of the quiet stall in the girls bathroom, Lena rolled her burgundy uniform sleeve up slowly. She gasped quietly, at the new words on her arm. As she read them across, she laughed out loud at the irony. 

_I don’t like math very much, do you?_

Lena could stop herself from continuing to laugh. Her soulmate was not a fan of maths but she had just come from calculus and was doing a physics based science fair project. Of course this had happened. She was sure her soulmate was still an excellent person, despite not enjoying maths as much as she herself did. 

The message had been signed with K. Lena ran through possible names as she let her mind wander, Keegan? Kallum? Kenneth? She thought of three of her awful male classmates with those names and could not possibly imagine spending eternity with them, wanting to gag at the thought. She was sure her K was much kinder, and smarter than them, definitely more mature. 

Lena got up from the stall and walked out the door, contemplating what to write back to her soulmate. As she was deep in thought, she ran directly into a boy with dirty blonde hair and a dirtier expression to match. It was one of her male classmates with the K names, Kallum. He dropped his lunch tray, splattering food on her black polished shoes. 

“Watch it Loser Luthor!” he sneered, “wouldn’t want anyone to think it’s okay for someone as lame as you to run into me”. He snatched his lunch tray off the floor as his friends snickered at the use of Loser Luthor. 

“Wow, truly the most original use of language if I’ve ever heard it”, Lena held her head high, eyeing him down with a cool gaze. 

“Watch your mouth Loser Luthor”, Kallum said, stepping closer to Lena, “or I’ll just have to do something about it”.

“What could someone as half-witted as you attempt to do to me? You would struggle to poor water out of a boot with instructions on the heel”, Lena steeled herself for retaliation. 

“Or I’ll get my buddies here to help beat the shit out of you”, Kallum turned on his heel and walked over to a table with his friends while Lena stood her ground. She willed herself to turn around and find a table, first retrieving a tray from the cafeteria food station and getting lunch. Her soulmate with a K would definitely be much nicer than Kallum, that much she was sure of. She shuddered at the meer thought of Kallum being the one. 

She sat down, carefully cleaning the spilt food off her shoes with a napkin and then pondered what to write to her soulmate. She was sitting alone, as usual, facing the window with a physics book propped open, making notes for her upcoming science fair project. Struck with inspiration, Lena began scribbling equations out then took out her black fineliner again. She wrote out neatly to her soulmate…

_(y^2+X^2-1)^3-x^2y^3=0 I do like maths, try plugging this equation in _

~~~~~~~~~  
Kara received the equation while she sat in her own math class. She stared back at it on her own arm, utterly flabbergasted. It was far beyond what she understood about math. She tried typing it into her own calculator but found she didn’t even have a y button. Whose calculator even has a y button? 

Kara kept the message to herself until the end of the day. She arrived home with Alex, to an empty house, a note tacked to the fridge. 

Gone grocery shopping, be back soon girls! -Mom

Alex pulled an apple out of the bowl and tossed one to Kara, who caught it, quite surprised at the gesture. Alex then sat down at their long dining room table and started pulling out her homework. Kara sat across from her, intrigued by how smart Alex was. It triggered something in her mind. 

“Alex, does your calculator have a y button?” Kara asked quietly. 

“Well yeah, it’s a graphing calculator”, Alex rolled her eyes, taking another bite of her apple. “Why? Interested in learning some math above pre-k level?”

“Could I borrow it for five minutes?” 

Alex shrugged and handed it over, flipping her book open to study a different problem. Kara, sitting across from her, rolled up her sleeve and began to type the equation out, stumbling over the foreign buttons. 

She smiled broadly at the calculator as she finished typing. It displayed a heart. Kara felt touched and couldn’t help but practically glow. Alex kept looking at her, then glanced down at the calculator. “Neat trick. Maybe you’re not such a hopeless case”, she snatched her calculator back, leaving Kara to her own thoughts.

**Notes for the Chapter:**

> Thanks again for the support! Let me know if you have any suggestions I can throw in!


	4. An Invitation

From when she had first received a message from K, they hadn’t stopped messaging each other. Lena still didn’t know her soulmate’s full name but she didn’t push it. There was no need for K to find out she was a Luthor, so why would she violate their privacy? 

The messages she received through the years were so full of kindness and support, something Lena wasn’t receiving from many other places. It started small, with a simple _good luck!_ before a test, to messages of support when Lillian talked down to her. Her soulmate was clearly someone bursting at the seams with energy and sunshine, and somehow everything amazing. It still shocked Lena that this ball of light was supposed to be hers, she was supposedly a cold and calculating Luthor. But K had decided she deserved love and support in every endeavour in life and if no one else would give it to Lena, they would. 

Lena had learned a fair amount about K but was still learning more every day. They had a sister named Alex, an amazing set of parents named Eliza and Jeremiah, an aptitude for running, a passion for English class, and a love for finding whatever was happening. Whether that be the neighbourhood block party or a protest in their hometown. The action somehow always found them. Lena loved getting messages about K’s adventures, or misadventures as they should more likely be put. 

_I fell in a creek today trying to talk to a fisherman about the fishing season for an article at my school newspaper!_

Lena loved receiving the messages as she watched K grow into quite the budding journalist, working an internship at the local paper. 

_Today I got to learn to surf! Alex is going to states and she was finally willing to teach me in exchange for me interviewing her for the local paper._

Lena also relished in the kindness that always appeared on her arm. Though it started small with tests in high school, it lead to congratulations being awarded for her graduation from MIT. K was there when her brother became estranged, but she gave no more information. K was there when she drifted further from Lillian, and took on greater responsibilities, even strongly considering changing her last name. She and K talked less as they got older, but she would still receive a check in message at least once a month. However small, they made sure to keep in touch, even when times got busy. 

The older she got, the more anticipation built for meeting her soulmate, it was the final puzzle piece. By the age of twenty-five she was a well-established , trying to make a better name for herself and distance herself from her family. K had taught her she was good enough to forge her own path. She was now the chief scientist and owner of a medical research company, MedTech, working to find cures for diseases. She felt like her work was rewarding in and of herself, but she was always wanting more. More cures, more time in the lab, more ways to help others. 

Lena had strayed far from the path originally set out for her, the business path, but this path was her own. From her undergrad at MIT to medical school, she had learned a lot, accelerating through all her programs. She has chosen something uniquely her own, something K had encouraged her to do. Because you only have one life, so you may as well live it doing something you love. That was what K was trying to do as a journalist. She still had a clear memory of the message she got when she got accepted to med school…  
 _Follow your heart Le! You’re gonna help so many people in your life. I am so unbelievably proud of you!_

Work had been especially busy lately, simply because Lena had wanted more lab time to complete hands on work. She was deep in thought, standing in front of her work station when she felt a tap on her back. Lena nearly jumped in surprise. 

One of her most diligent employees, Alex, stood behind her. Alex only worked part time, the other part she had family matters to attend to, but Lena still believed her to be one of the company’s best assets. “Alex, you frightened me”, Lena pushed her safety glasses up her nose. 

“You shouldn’t spend too many late nights here! You’re going to go stir crazy.” Alex chuckled, flipping her curly brown hair out of her face. 

“I know when enough is enough”, Lena said sorely, “I was planning to take tomorrow evening off”. Alex quirked an eyebrow, knowing full well Lena may end back up in the lab immersed in chemicals and biotechnology. 

“If you are being truthful about taking tomorrow off, come out with me tomorrow night”, Alex proposed, “my sister is moving to National City for a new job and Maggie and I are taking her out for drinks”. 

“I wouldn’t want to impose”, Lena said, fiddling with a beaker aimlessly, “that’s your family”.

“Lena, you would not be imposing. Besides Kara may puke if she spends too much time third-wheeling Maggie and I”

“Well, you’ve convinced me. I will take tomorrow off”, Lena conceded. Alex gave her the information and time of the outing as she left through the lab door. 

“Don’t stay here too late!” she called as the door banged shut. 

At that, Lena decided it was time to go home, being 10pm already. She cleaned up her work station and walked to the edge of the lab, removing her lab coat. She was greeted by a message on her arm. 

_Starting my new job tomorrow! Finally going to be a real journalist!_

Lena smiled broadly. K was finally getting their big break and she was thrilled. As she got ready to leave, she wrote a message back. 

_Good luck! Be yourself and you will be amazing!_


End file.
